The global burden of disease from alcohol abuse and alcohol organ damage is enormous. To improve treatment and monitoring there remains a need for better biomarkers of alcohol consumption and alcohol-induced organ damage. Phosphatidylethanol (PEth) is a nonoxidative, long-lasting metabolite of ethanol described as a blood biomarker for alcohol ingestion. PEth may also play a role in cell and organ damage. In Phase I, the contractor successfully generated antibodies to PEth and an un-optimized research Enzyme-Linked Immunosorbent Assay (ELISA). During the current funding period, a cell-based clinical assay for rapid quantification of PEth from blood samples will be generated. This ethanol biomarker assay should then be validated for use in distinguishing heavy from moderate drinking in subjects up to 2 weeks post alcohol consumption. Future research is anticipated using these reagents and tools to test the possible role of PEth in ethanol-induced organ damage.